package cn.smart.epic.core.util;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * @Auther Uncle_Z
 * @date 2017/9/6 0:01
 * @Email:2545375@qq.com
 * @Descrition Spring的ApplicationContext的持有者,可以用静态方法的方式获取spring容器中的bean
 * @since 1.0
 */
@Component
public class SpringContextHolder implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        SpringContextHolder.applicationContext=applicationContext;
    }

    public static ApplicationContext getApplicationContext(){
        assertApplicationContext();
        return applicationContext;
    }


    public static <T> T getBean(String beanName) {
        assertApplicationContext();
        return ((T) applicationContext.getBean(beanName));
    }

    public static <T> T getBean(Class<T> requiredType) {
        assertApplicationContext();
        return applicationContext.getBean(requiredType);
    }

    private static void assertApplicationContext(){
        if (SpringContextHolder.applicationContext==null) {
            throw new RuntimeException("applicationContxt属性为null,请检查");
        }
    }
}
